No abstract

The highly efficient, regioselective, and enantioselective transfer hydrogenation of α-keto ketimines and reductive amination of diketones by Brønsted acid catalysis is described. A series of chiral α-amino ketones is prepared in high yields (up to >99%), excellent regioselectivities (up to >99:1), and enantioselectivities (up to 98% ee). This method has broad substrate scope.

Here, a novel Ru(II)-organic complex (Ru-PEI-ABEI) with high electrochemiluminescence (ECL) efficiency was proposed to construct a sensitive quenching-typed ECL biosensor for C-peptide (C-P) measurement based on the double quenching effect of dopamine (DA). The high ECL efficiency of Ru-PEI-ABEI was originated from the dual intramolecular self-catalysis including intramolecular coreaction between polyethylenimine (PEI) and Ru(bpy)(mcbpy), and intramolecular ECL resonance energy transfer (ECL-RET) from N-(aminobutyl)-N-(ethylisoluminol) (ABEI) to Ru(bpy)(mcbpy), which would generate a strong initial ECL signal. Through sandwiched immunoreaction and 3D DNA walking machine, a certain amount of target C-P was converted to a large amount of intermediate DNA that could further trigger hybridization chain reaction (HCR) to introduce into massive DA which not only could quench the ECL of Ru(bpy)(mcbpy), but also quench the ECL of ABEI. Thus, the double quenching effect of DA would effectively quench the ECL of Ru-PEI-ABEI, leading to an obviously decreased final ECL signal. Thus, a sensitive quenching-typed ECL biosensor was constructed for C-P detection with a linear range from 50 fg mL to 16 ng mL and an estimated detection limit of 16.7 fg mL. The dual intramolecular self-catalyzed strategy and the double quenching strategy based on one quencher to the same luminous reagent proposed in this work would provide new thought in both ECL signal enhancement and quenching efficiency improvement.

Recently, two-dimensional (2D) nanostructures, such as graphene and few-layer MoS 2 , have been applied to wide fields based on their intriguing performances, and they contribute to developments of clean energy, biomedicine, and environmental protection. The synthesis of 2D nanostructures involves chemistry, materials, and biologyassociated interdisciplinary knowledge. Nevertheless, desired strategies that can be comprehensively and safely achieved by undergraduates or academic trainees are largely restricted considering the uses of toxic and pyrophoric reagents, high-risk manipulation, expensive instruments, and a time-consuming test period. Herein, chemically fundamental experiments are integrated with scientific frontiers, achieving the development of undergraduate's experimental projects based on up-to-the-minute academic results. In order to promote the high-efficient study and eliminate the risks among our learners, the virtual simulation courses are well-integrated, and students can independently complete the synthesis of 2D MoS 2 nanomateirals without the face-to-face guidance of mentors. Significantly, several characteristics are equipped in this project: (1) Students can master the uses of oxygen-sensitive, moisture-sensitive reagents and skills for operating high-risk reactions via the virtual system; (2) Universal preparation approaches of 2D nanomaterials, based on the Schlenk technique, are presented; (3) Students' understanding of MoS 2 monolayer characterization, properties, and applications is remarkably increased. This project aims at inspiring students' understanding for scientific frontiers, improving their academic and innovative skills, as well as expanding their advanced perspective.